Oil regulator for pneumatic tools



May 1, 1934. F. B. HAMERLY OIL REGULATOR FOR PNEUMATIC TOOLS Filed 001:.l, 1930 A TTO Patented May 1, 1934 UNITED STATES PATENT OFFICE OILREGULATOR FO R PNEUMATIC TOOLS Application October 1,

3 Claims.

This invention relates to an improved oil regulator for portablepneumatic and other tools.

In portable pneumatic tools, automatic lubrication of the working partsof the tools by carrying the oil into the tool with the incoming air hasreceived considerable attention by the manufacturers of such tools.

In these tools and more particularly with respect to tools of the typein which rotor devices with piston blades are employed as the motorunits, it has been proposed heretofore to provide a chamber within thecasing of the tool to serve as a reservoir for the lubricating oilrequired, and to have this reservoir in communication with r the maininlet air passage of the tool in advance of the motor through arelatively small opening which is controlled by a needle valve. The mainobjection to this construction is that the opening clogs if unclean oilis used by reason of the close adjustment required between the wall of vthe opening and the valve in order to feed the oil very slowly from thereservoir to the air duct or just enough to prevent the moving parts ofthe tool getting dry and starting to cut and wear.

The object of my invention is to providean oil regulator so constructedand designed that it will not clog and thus keep open at all times" theconnection between the reservoir chamber and the air duct so that therequired flow of oil to the tool may be maintained, and also strain orfilter the oil as it passes out of the reservoir and thus supply onlyclean oil to the tool.

Specifically, I provide a cartridge type of device insertable in theconnection between the reservoir and the inlet air passage of the tool,with a packing of felt or other oil cleaning and straining material inthe cartridge through which the oil must flow. The cartridge is soconstructed and arranged in the tool that it may be readily and easilyremoved from time to time for renewal of the felt or packing materialemployed in the device. The closing cap of the cartridge engages thepacking to compress it to the extent required to control the flow of oiltherethrough.

The invention consists further in the mattershereinafter described andclaimed.

In the accompanying drawing:

Fig. 1 is a side view with parts in section of a portable pneumatic toolprovided with the oil regulator of my invention;

Fig. 2 is a top plan view of the motor section of the tool with the capmember removed to show the oil regulator which is in section;

1930, Serial No. 485,790

Fig. 3 is a perspective view of the several parts composing theregulator; and

Fig. 4 is a horizontal sectional view taken through the rotor and itsshell.

The tool shown in the drawing is of the type having a supporting frame 1with a gear case section 2 on its under side and feed screw and motorsections 3, 4, respectively, on its upper side. The several sectionsreferred to are secured together in assembled relation in any suitablemanner, as by screws and bolts, some of which are shown in Fi 1.

The motor section 4 has an outside casing 5 provided with an inletpassage 6 to which is connected a hollow handle 7 through which thecompressed air required to operate the tool is supplied. A manuallyoperable throttle valve (not shown) is associated with the handle 7whereby the operator may control the supply of motive fluid to the tool.The tool has a dead handle '7 on its side opposite the live handle 7,and as these handles extend laterally outward from the tool they providemeans whereby the tool may be conveniently held and carried.

Located within the casing 5 is a rotor housing or shell 8, in which is arevoluble rotor 9 having shaft extensions at its opposite ends. Saidextensions are journalled in end plates at the opposite ends of theshell 8; which plates and shell are held against rotation as in toolstructure of this kind. The motor section 4 is arranged on the frame 1with the axis of the rotor 9 vertical and connected at its lower endwith the spindle 2 of the tool through gearing in the gear case section2. The upper end plate 10, as shown in Fig. 1, is clamped between theupper end of the shell 8 and the cap structure at the top of the motorcasing. This structure provides a support and housing for the governorand the valve operated thereby in the rotation of the rotor 9 toautomatically control the amount of motive fluid supplied thereto inaccordance with the load on the same. The cap structure includes anouter cap member 11 and an inner member 12, which is interposed betweenthe cap member 11 and the top of the motor casing 5, as shown in Fig. 1.The bolts which secure the casing 5 to the frame 1 may be made longenough to take in the cap structure to clamp it and its parts togetherand to the casing of the motor. The holes for these bolts are shown at4%4 in Fig. 2.

r The member 12 is preferablyin the form of a casting in the shaperequired to confrom to the contour at the upper end of the motor sectionof the tool, and is 'cored out to provide an oil containing chamber orreservoir 13, which as shown in Fig. 2 extends in a circumferentialdirection about the axis of said section from points on opposite sidesof an annular space 14 about the exterior of a bushing 15 in which isslidably fitted a valve 16 operated by the governor mechanism of thetool. The reservoir 13 is provided with a filling opening 17 normallyclosed by plug 18, as shown in Fig. 2.

In accordance with my invention, the casting 12 is cored out to providea bore 19, which extends through the casting at a point adjacent one endof the reservoir 13 and interposed between the same and the space 14, asshown in Fig. 2. The casting 12 is provided with ports 20, 21, onopposite sides of the bore 19. The port 20 connects the bore 19 with thespace 14, while the port 21 connects the bore with the adjacent end ofthe chamber 13, as shown in Fig. 2.

The oil regulator of my invention is disposed in the bore 19, and ispreferably made in the form of a cartridge comprising a tubular memberor sleeve 22 of a diameter to fit within the bore 19, and containing apacking 23 of suitable flow controlling and oil filtering material, suchas felt. The inner end of the sleeve 22 is closed by an end wall 24. Theouter end of the sleeve is made open and is internally screw-threaded toreceive a threaded closing plug 25, which is provided with an inwardextension 26 to engage and compress the packing 23 to render it denseenough to serve as a flow regulator and an eifective filter or screenfor the oil passing therethrough. In order that the oil may pass throughthe packing from the reservoir 13 to the space 14 about the exterior ofthe bushing 15, I provide the sleeve 22 with diametrically arrangedslots 27, 27, disposed to register respectively with the ports 20 and21, as shown in Fig. 2.

The density and length of the packing 23 selected is such that thepacking when compressed by the closing plug 25, will allow only theproper amount of oil to pass therethrough and thus avoid wasting of theoil. The packing being in contact on one side with the oil in thereservoir 13 through the port 21 will absorb the oil and furnish it tothe compressed air on the other side of the packing which is in contacttherewith through the port 20. Compressed air entering the chamber 14each time the tool is started passes through the packing 23 into the oilreservoir 13 creating a pressure on the oil therein, and at the sametime removing any dirt or other foreign matter collected on the packing.When the air is turned off from the chamber 14, as by closing thethrottle valve in the handle '7, the air travels in the oppositedirection from the reservoir carrying oil with it through the packing 23and into the motor section of the tool to lubricate its parts. Thisoiling system does not clog and feeds oil even if considerable dirt getson the felt. It does not prevent the felt from absorbing the oil and thecompressed air in the chamber 14 also being in contact with the packing23 will carry oil from the packing along with the air to the workingparts of the tool.

The sleeve 22 has a pressed fit in the bore 19, and therefore preventsany oil from passing from the reservoir into the chamber 14 exceptthrough the felt. This effectively regulates the amount of oil fed intothe air line of the tool, and also prevents grit and dirt which might bein the oil from passing into the tool to injure or score its workingparts. Moreover, the dirt does not prevent the oil from coming incontact with the felt.

In order that the compressed air admitted into the inlet passage 6 mayenter the shell or housing 8 to operate the rotor 9 therein, I providethe bushing 15 with a plurality of ports 28 arranged to permit the airto fiow from the passage 6 into the interior of the bushing when thevalve member 16 uncovers said ports. The end plate 10 is provided with apassage 29 which registers with the lower open end of the bushing 15.The passage 29 connects with a radial passage 30 in the end plate 10,which passage leads to a groove 31 which feeds live air to the bottomsof the slots 32 in which the piston blades 33 of the rotor have slidingmovement. The motor is so constructed that the live air may pass fromthe bottoms of the slots to the rear or pressure sides of the bladesbeyond the periphery of the tool through passages 34 to effect rotationof the rotor as in motors of this design. The motor is also constructedto permit the air to exhaust from the shell 8 through exhaust ports 35to the exhaust nozzle or deflector 36 on the exterior of the tool. Theend plate (not shown) at the lower end of 100 the rotor is similar tothe plate 10 and has the radial passage and the groove so that both endsof the rotor will be supplied with motive fluid at the same time. Forconnecting the passages 29 whereby both ends of the rotor may be sup-105 plied with motive fluid, the housing or shell 8 is provided with alongitudinal passage 3'7, as shown in Fig. 1.

It is to be of course understood that the oil r gulator of invention asherein shown and de- 110 scribed is not restricted in its use to theparticular type of tool herein referred to. The particular type of toolshown has merely been selected as an illustration of the application ofmy improved oil regulator for pneumatic tools. Regardless of the type oftool, the oil regulator is disposed in the passage which connects theoil reservoir with that portion of the live air duct of the tool inadvance of the motor thereof.

I claim as my invention: 120

1. In a pneumatic tool having a motor and a live air duct thereto and achamber adapted to contain lubricating oil, passage providing meansconnecting the chamber with the live air duct in advance of the motor,and an oil regulator disposed in said passage, said regulator consistingof a tubular member with a packing material therein and having slots inregister with the portions of the passage on opposite sides of thetubular member, and a non-yielding plug adjustably mounted in saidmember and directly engageable with the packing for compressing the sameand holding it compressed to control the flow of oil therethrough. V

2. An oil regulator in the form of a cartridge or self-contained unitand insertable as such in a pneumatic tool, comprising a tubular holderopen at one end and closed at the opposite end and having slots in thesides thereof, a packing fitting in said holder and underlying said.slots, and a screw plug fitting in and closing the open end of theholder, said plug having its outer and exterior of the holder and itsinner end directly engaging the packing for compressing the packing inthe holder against its closed end on screwing the plug into the holder.

3. In a pneumatic tool having a motor and a live air inlet ducttherefor, a member incorporated in the structure of the tool and havinga chamber to contain a supply of lubricating oil for the 1 a tubularholder tightly fitting in the bore to close the same against leakage ofoil from the chamber, said holder having slots in register with thepassage which intersects the bore, a packing in said holder, and a screwplug fitting in the holder and. directly engageable with the packing tocompress the same to control the flow of oil from the chamber to theduct.

FRANK B. HAMERLY.

